[The antioxidative chromane structure of alpha-tocopherol protects against the consequences of arachidonic acid release in the pulmonary vascular bed (author's transl)].
In the model of isolated, ventilated and perfused rabbit lungs release of arachidonic acid results in an increase of pulmonary vascular resistance and permeability. The former can be ascribed to cyclooxygenase products, the latter to lipoxygenase products of arachidonic acid. The effect of alpha-tocopherol on the increase of pulmonary vascular resistance and permeability either after the addition of arachidonic acid to the perfusion fluid or after stimulation of arachidonic acid liberation by Ca-ionophore A 23187 was investigated. It is possible to distinguish a membrane effect of the phytol side chain of alpha-tocopherol and an antioxidative effect of its chromane structure: Phytol augments the increase of pulmonary vascular resistance and permeability, whereas the chromane-structure decreases both to a large degree. The possibility of antioxidative therapy in disturbances of pulmonary vascular permeability is discussed.
D000818:Animals; D001095:Arachidonic Acids / Q000097:blood*; D001794:Blood Pressure / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D002199:Capillary Permeability / Q000187:drug effects; D002264:Carboxylic Acids / Q000494:pharmacology; D002839:Chromans / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D011652:Pulmonary Circulation / Q000187:drug effects*; D011817:Rabbits; D014655:Vascular Resistance / Q000187:drug effects*; D014810:Vitamin E / Q000494:pharmacology*
D001095:Arachidonic Acids; D002264:Carboxylic Acids; D002839:Chromans; D014810:Vitamin E; D000001:Calcimycin; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; D007213:Indomethacin
Protektiver effekt der antioxidativ wirksamen Chromanstruktur des Tocopherols auf die Folgen stimulierter Arachidonsäure-Freisetzung in der pulmonalen Strombahn.